Machine sucks carbon from air like a Ghostbusters beam snarfs up ectoplasm

This machine sucks carbon out of the air like a Ghostbusters beam snarfing up ectoplasm. The idea is that if we can build millions of these babies, and find a good place to stick the carbon they capture, we can start to bring down Earth's already-dangerous levels of atmospheric carbon dioxide. The technology at the core of the device is not new. "People have done this for a long time," [says David Keith, inventor of the device]. "There were commercial processes that took CO2 out of the air, in fact, in the 1950s, so there's no mystery that we can do it." Keith says taking tens of thousands of tons of CO2 out of the air every year "isn't as hard as you think." Skeptics disagree, and argue that so-called "air capture" of carbon dioxide will never be economically realistic. But Keith is sanguine about their objections, and argues that if no one is pushing the envelope on this...